The present invention relates to a novel composition of matter, 9.alpha., 21-dichloro-16.alpha.-methyl-1,4-pregnadiens-11.beta., 17.alpha.-diol-3,20-dione-17-(2'-furoate) monohydrate, also designated mometasone furoate monohydrate, process for its preparation, and pharmaceutical preparation thereof.
Mometasone furoate is known to be useful in the treatment of inflammatory conditions. The compound is prepared by procedures disclosed in U.S. Pat. No. 4,472,393, which patent is hereby incorporated by reference.
When aqueous pharmaceutical compositions, e.g. suspensions, containing anhydrous mometasone furoate were subjected to stability testing by rotating for four weeks at room temperature and 35.degree. C., formation of a crystalline material which is different from the anhydrous mometasone furoate crystal was observed in suspension. Experiments were designed to determine the nature of the crystalline material. It was postulated that formulation of mometasone furoate compositions with the stable crystalline form would reduce the probability of crystal growth during long term storage of the suspension leading to a more stable product.